Your Bikes can be upgrade to perform better and provide you with better profits by upgrading them.
You can find the bike's stage progress in the Collection list and clicking the upgrade button.
To reach each Stage kit you must build a certain number of the same bike. Alternatively, you can pay 
to skip the requirements for unlocking that particular stage.
| Stage kit | Cars needed | Profit increase | Cash unlock |
|---|---|---|---|
| Stage kit 1 | 1 | +0% | n/a |
| Stage kit 2 | 10 | +10% | 15
|
| Stage kit 3 | 25 | +25% | 30
|
| Stage kit 4 | 100 | +50% | 50
|
Note: The bike stage kit "profit increase" applies to all cars of that type you currently have for sale.
Example: If you create 9 bikes they could be for sale at 1,000 
each. After building the 10'th bike "all" 9 bikes including the 10'th one you built will be for sale at the new +10% sale price. Meaning 1,100 or more after quality check increase.
